Readily separable torque transmitting coupling



July 18, 1961 BLACHLY 2,992,715

READILY SEPARABLE TORQUE TRANSMITTING COUPLING Original Filed Aug. 27, 1959 3&1. i

2 Sheets-Sheet 1 ly 1961 D. L. BLACHLY 2,992,715

READILY SEPARABLEI TORQUE TRANSMITTING COUPLING Original Filed Aug. 27, 1959 2 Sheets-Sheet 2 .Uz-zaZa? LBZaahZy I United States Patent a 1 Claim. c1. 192.- I67) This invention relates broadly to readily separable torque transmitting connections and refers more particularly to a driving connection for coupling the agitator shaft of a food comminut-ing or blending machine to its motor-driven drive shaft.

The copending application, Serial No.836,459, filed August 27, 1959, of which this application is a division, affords a complete disclosure of the class" of food'comminuting and blending machines'for which the coupling device of this invention is specifically intended. For information concerning coupling devices previously available for this purpose, reference may be had to the Reissue Patent No. Re. 24,607, granted February 24, 1959, to A. W. Seyfried.

In food comminuting and blending machin'eswhic'h re.- quire a readily separable driving connection, the drive motor is housed within the base of the machine, with its drive shaft protruding vertically through the top thereof to be drivingly coupled to the shaft of the agitator. The agitator shaft is journalled in the bottom of a mixing vessel, removably seated on top of the base. Absolute coaxiality between the motor shaft and the agitator shaft is, therefore, unlikely, to say the least. Hence, the coupling by which the driving and driven shafts are connected must be sufliciently flexible to accommodate some misalignment between the shafts.

Also,since the machines for which this invention is intended are household appliances, and used for the most part 'by women, they should be as quiet in operation as possible. Obviously, therefore, the coupling should not be noisy, nor should it have vibration producing play which, if present, multiplies the v-ibration resulting from the action of the agitator. .blades upon the vessel contents, and causes the machine to travel, i.e. hop about on the counter top. On the contrary, the coupling should be positive when engaged, and sufiiciently resilientlto absorb agitator produced vibration.

The coupling of this invention meets all these objectives.

The purpose and object of this invention thus is to provide a readily separable torque transmitting coupling which will provide a smooth, positive drive from the motor shaft to the agitator shaft, which is quiet and efiicient in operation, and rugged enough to stand up under conditions which often border on abuse.

It is also an object of this invention to provide a readily separable torque transmitting connect-ion of such simple design and construction that it may 'be easily and inexpensively produced.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claim, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claim.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in Which:

Patented July 18 FIGURE 1 is a side view of a food comminuting and blending machine equipped with the coupling of this invention, with the mixingvessel shown lifted off the motor base, andwith the adjacent portions of the vessel and base broken away and in section to better illustrate the coupling; l

FIGURE 2 is a top plan view of the base;

FIGURE 3 is a bottom view of the mixing vessel;

FIGURE 4 is a fragmentary detail view partially in section and partially in elevation, illustrating an important feature of the invention;

FIGURE 5 is a perspective view of the driving and driven elements of the coupling shown separated from the shafts to which they are attached in use; and

FIGURE 6 is a detail sectional view through the hub portions of the drivingand driven coupling elements, to show the manner in which they are secured to their respective shafts. i

Referring now particularly to the accompanying drawings, the numeral 7 designates generally the base of a food cornminuting and blending machineidentical to that which forms the subjectmatter of the aforesaid copending application Serial No. 836,459, filed August 27, 1959. The base 7 houses a drive motor (notshown) the shaft 8 of which projects up through the top of the base to be drivingly coupled to the shaft 9 of an agitator 'in the bottom of a mixing vessel 11 when the mixing vessel is properly placed on the base.

The agitator 10 comprises a plurality of mixing blades fixed to the shaft 9 which is journalled in a bearing 12 centrally fixed in a removable closure 13 for the bottom of the mixing vessel. The removable bottom 13 telescopes into a neck 14 at the bottom of the jar which provides the body of the mixing vessel, with a suitable resilient gasket 15 therebetween, and it is held in place by a collar 16 threaded onto the neck 14.

As shown in FIGURE 3, the collar 16 is hexagonal in external outline and, when-in place on'the base, seats upon three resilient L-shaped pads 17 fixed tobosses 18 whichpro'ject from the top of the base. As more fully explained in the aforesaid copend'ing application, the reception of the six-sided co'llar 16 by. the three 'L-shaped pads holds the mixing vessel 'agains't rotation in an uprightposition with its agitator shaft coupled to the motor shaft in as good alignment therewith as can be expected under the circumstances, while'sti ll leaving the mixing vessel free for quick and easiyre moval from the base.

The coupling by which the motor shaft and the agitator shaft are separably connected, indicated generally by the numeral 19, comprises a driving element 20 and a driven element 21. The former consists of a rigid metal disc 22 having an extruded hub 23 at its center which is tapped to have threaded engagement with the end of the shaft 8, as clearly shown in FIGURE 6, and a rubber molding 24 vulcanized or otherwise bonded to the top face of the disc.

The rubber molding 24 has a flat disc-like base 25 coextensive with the disc 22, and six resilient equispaced tits 26 which project up from the base at equal distances from the axis of the coupling. Each of the tits is substantially conical, but has its axis inclined to the plane of the base 25 and the disc 22 in the direction of shaft rotation, so that an upright line on the front surface of the tit leans slightly forward, i.e. in the direction of rotation. This condition is best illustrated in FIGURE 4. Preferably the rubber molding 24 has reinforcing spokes 27 which rise slightly above the top of its base 25 and extend from the hub of the molding to each tit.

The driven element 21 of the coupling is essentially a wheel, preferably molded of thermoplastic material 01' disposition of thespokes or arms.

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the like, and has a hub portion 28 with a metal insert 29 therein. The insert 29' has a tapped bore extending down from the top thereof, which has threaded engagement with the adjacent lower end of the agitator shaft 19,,as clearly. shown in FIGURE 6. a

-arim 31 connects the outer ends of these spokes or !arms.-y Attention is directed to the. specific shape and FIGURE 3, each spoke or arm has a flat side 32lying in a plane containing the'agitator shaft axis and extending-fradiallyfltherefrom. .Since there are six spokes or arms, there is of course onefor each of the tits 26, and

-the arms or spokes, or at least their flat sides 32, are

angularly equispaced. Hence, when the two coupling elements are coa'xially juxtaposed and engaged as a result ,of the mixing vessel being placed upon the motor base, and torque is being transmitted, each tit has substantially a line of contact along its front or leading surface with the fiat side 32 of the arm or spoke in front of it.

,In'theevent of misalignment between the driving and driven members, or if for some other reason certain -of the tits engage their respective spokes or arms before the ;others ;do, the first to engage will yield and permit the remaining tits to contact their respective spokes or arms and pick up their'share of the load. Y This resilient displacement of the tits is facilitated by the slight forward inclination of their leading edges 26', :since the apex'portions of the tits are obviously the most 'yielda'ble portions thereof. The forward inclination of the tits also has the advantage of increasing the frictional grip between the driving and-"driven coupling members, .and thus resisting axial separation thereof while torqueis being transmitted.

The degree to which the tits are inclined is not critical, except that it should not be excessive; and, of course, in no event would it be desirable to have the leading edges 'of the tits slant back from true perpendicularity. Such reclination would result in the stifiest portions of the tits-namely, their base portions, being the first to pickup the torque load. "Resilient deformation of the tits toenable all of them'to share the load would be unlikely under the circumstances.

While the, relative disposition of the driving and driven elements shown and described has been found entirely satisfactory and, in fact, preferable, it should be understood that the two could be interchanged, i.e. the spoked wheel could be the driving element and'the disc with the tits could be the driven element. tits would be inclined as shown to assure the torque load being picked ,up 'first by the outer ends of the tits.

As best seen in In either case, the

In conclusion, may it be said that this invention provides a very satisfactory and efiicient readily separable torque transmitting connection, especially well adapted to coupling the motor shaft of a food oomminuting and blending machine, with-its agitator shaft and that the success of the invention no doubt'lies in its combination of the conical inclined resilient'tits with the fiat unyielding or rigid spokes engaged thereby during torque transmission. I

What is claimed asmy invention is: p

A readily separable torque'transmitting coupling-by which rotation maybe transmitted from a drive shaft to a driven shaft when said shafts are placed in endwise substantially coaxial juxtaposition, said coupling comprisingz. complementary rigid and yieldable coupling members, each secured to an end portion of on e;of said shafts for rotation therewith; the rigid coupling member having a hub portion and a plurality of rigid arms radiating therefrom, each of said arms havinga surface substantially radial to the shaft axis and said surfaces of the arms being angularly equispaced; the yieldable coupling member comprising a rigid dischflYing an axially outer face which is substantially normal to; the axis of the shaft to which said y-ieldable couplingmemher is secured, which outer face is contiguous to the rigid coupling member when the coupling membersare engaged; and a plurality of resilient conical tits secured at their bases to the axially outer face of saiddisc and projecting into the spaces between said rigid arms when the coupling members are engaged, there being one of saidtits for each of said rigid arms, and said tits being equispaced from one another and from the shaft axis, each of said tits having its axis inclined to said axially outer face of the disc and having a leading surface disposed at an acute angle to the outer face of the base leaning towards the radially disposed surface of the rigid arm with which the tit engages during the transmissionof torque by the coupling, so that initial engagement between the tit and said surface on the arm takes place at the outermost resilient portion of the tit whereby each tit can resiliently yield in response toload imposed upon it by its cooperating arm to enable other tits to engage their respective arms in the event-of slight misalignment of the axes of the two coupling members.

2,755,900 Seyfried July 24, 1956 2,930,596 Waters Mara 29,. 1960 

